DS21554L Maxim Integrated Products, DS21554L Datasheet - Page 72

• Manufacturer Part Number: DS21554L
• Description: IC TXRX E1 1-CHIP 5V 100-LQFP
• Manufacturer: Maxim Integrated Products

Specifications of DS21554L

• Function: Single-Chip Transceiver
• Interface: E1, HDLC, J1, T1
• Number Of Circuits: 1
• Voltage - Supply: 4.75 V ~ 5.25 V
• Current - Supply: 75mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 100-LQFP
• Includes: Remote and AIS Alarm Detector / Generator
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power (watts): -

14.3.
As a basic guideline for interpreting and sending HDLC messages, the following sequences can be
applied:
14.3.1.
1. Enable RPS interrupts
2. Wait for interrupt to occur
3. Disable RPS interrupt and enable either RPE, RNE, or RHALF interrupt
4. Read RHIR to obtain REMPTY status
5. Repeat step 4
6. Wait for interrupt, skip to step 4
7. If POK = 0, then discard whole packet, if POK = 1, accept the packet
14.3.2.
1. Make sure HDLC controller is done sending any previous messages and is current sending flags by
2. Enable either the THALF or TNF interrupt
3. Read THIR to obtain TFULL status
4. Repeat step 3
5. Wait for interrupt, skip to step 3
6. Disable THALF or TNF interrupt and enable TMEND interrupt
7. Wait for an interrupt, then read TUDR status bit to make sure packet was transmitted correctly.
checking that the FIFO is empty by reading the TEMPTY status bit in the THIR register
Basic Operation Details
a. If REMPTY=0, then record OBYTE, CBYTE, and POK bits and then read the FIFO
b. If REMPTY = 1, then skip to step 6
a. Disable RPE, RNE, or RHALF interrupt, enable RPS interrupt and return to step 1.
a. If TFULL = 0, then write a byte into the FIFO and skip to next step (special case occurs when
b. If TFULL = 1, then skip to step 5
Example: Transmit an HDLC Message
the last byte is to be written, in this case set TEOM = 1 before writing the byte and then skip
to step 6)
Example: Receive an HDLC Message
a1. if CBYTE = 0 then skip to step 5
a2. if CBYTE = 1 then skip to step 7
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